Process for treating artificial casein fibers



Patented Dec. 5, 1939 PROCESS FOR TREATING ARTIFICIAL CASEIN FIBERS Marino Fortunato, Milan, Italy, assignor to Montecatini Societa Generale per llndustria Mineraria e Chimica, Milan, Italy, a corporation of Italy No Drawing.

Application November 28, 1938,

Serial No. 242,766. In Italy December 29, 1937 2 Claims. ((31 8-55) It is well known that it is possible to obtain an artificial fiber similar to natural wool, starting from casein. This product is hereinafter referred to as casein wool.

The behaviour of this fiber in dyeing with chrome colours is rather different from that of natural wool, especially in respect of the shades obtained. This is a great disadvantage, since it precludes from dyeing with chrome colours a 10 mixed fiber of natural and casein wool, preventing thus one form of application of casein wool, which otherwise should be the bestjin practice.

I have now found that, when casein wool is previously treated with a dilute solution of monosodium phosphate, its behaviour in respect to chrome colours becomes similar to that of natural wool. I

Such treatmentmay be carried out on the casein wool fiber as well as directly on the mixed 2 fiber of casein and natural wool.

Example 1.A mixture of natural and casein wool is treated during 30 minutes in a bath containing 1-2 cc. monosodium phosphateg-to the litre, at 4050 C. It is washed and neutralised with ammonia; 4% of previously dissolved diachrome blue B (Chromoxanreinblau B of I. G.-

Schultz, 7th edition, volume 2, page 59) then added, and the dyeing treatment is commenced at about 50 C., in the presence of 15% crystallised sodium sulphate. The bath is slowly brought to the boil and 0.5-1% acetic acid is added. The material is boiled for about 20 minutes and thedyestufi exhausted by means of 1-2% acetic acid: 'The bath is cooled and after the addition of 1% sodium or potassium bi-' chromate it is" brought again to the boil for about 20-30 minutes. The material is then washed.

Example 2.A mixture of natural and casein 40 wool is treated for.30 minutes at 40-50 C. in a bath containing 1-2 cc. monosodium phosphate to the litre. It is washed and neutralised with ammonia; 2% of previously dissolved alizarine Blue Black B (Alizarinblauschwarz B of I. G.- Schultz, 7th edition, volume 1, page 529, No. 1195) is added, and the dyeing is started atabout C., in the presence of 10% crystallised sodium sulphate. The bath is slowly brought to the boil and 1-2% acetic acidis added. Boiling is continued for 20 minutes and the dyestufi is exhausted by means of 1-2% formic acid. The bath is cooled'and after addition of 1% sodium or potassium bichromate it is brought again to the boil, which is maintained for about 20-30 minutes. The material is thenwashed.

The preliminary treatment with monosodium phosphate may be" a first step in dyeing, ac-- cording to the above examples, but itmay be carried out also as a separate step, since the fiber which has been treated in the manner described can be dyed later on, even by other dyers than those who carried out the preliminary treatment. In either case it is possible, by using any chrome colour whatever, to obtain on either the casein wool fiber alone, or the mixed fiber, a homogenous dye, equal to that obtained on the unmixed natural wool.

Having now described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is:- ,1. The process for preparing artificial fibers produced from casein for dyeing with chrome dyes, which comprises treating the fibers with a dilute aqueous monosodium phosphate solu- 

